1. Field of the Invention
The present invention relates to a honeycomb filter and a method for manufacturing a honeycomb filter.
2. Discussion of the Background
Conventionally, particulate matter (hereinafter, also referred to as PM) is contained in exhaust gases discharged from an internal combustion engine such as a diesel engine, and in recent years, this PM has raised serious problems as contaminants harmful to the environment and the human body.
For this reason, various filters using ceramics honeycomb filters including cordierite, silicon carbide or the like have been proposed as filters that capture PM in exhaust gases to purify the exhaust gases.
Moreover, a honeycomb filter formed by a honeycomb structure of a lamination type manufactured by laminating lamination members including inorganic fibers is known (for example, see WO2005/005018 A1, WO2005/000445 A1).
WO2005/005018 A1 discloses a honeycomb filter in which a large number of lamination members mainly including inorganic fibers are laminated and the laminated lamination members are fixed in a metal casing by a pressure from end members on both ends thereof.
Further, WO2005/000445 A1 discloses a honeycomb filter using a lamination member in which inorganic fibers are oriented more along a direction perpendicular to a forming direction of through holes than a direction parallel to the forming direction of through holes.
FIG. 10A is a perspective view schematically showing a lamination member and an end member forming the honeycomb filter described in WO2005/005018 A1, and FIG. 10B is a perspective view schematically showing a state of manufacturing a honeycomb filter using the lamination members and the end members shown in FIG. 10A.
Here, in FIG. 10B, an upper portion of the round pillar-shaped metal casing is not shown.
As shown in FIG. 10B, in a honeycomb filter 300 described in WO2005/005018 A1, a laminated body 110b is formed by laminating sheet-shaped lamination members 10b each having a large number of through holes 11b and a wall portion 13b separating the through holes 11b as shown in FIG. 10A, so that the through holes 11b are superposed on one another in a longitudinal direction (the direction shown by an arrow “a” in FIG. 10B).
Here, the state in which the lamination members 10b are laminated so that the through holes 11b are superposed on one another refers to a state in which lamination members 10b are laminated so that each of the through holes 11b formed in the adjacent lamination members 10b communicate with each other.
Moreover, an end member 10c having through holes 11c formed in a checkered pattern therein is placed on an end portion of the laminated body 110b and the end member 10c is fixed to a metal casing 23 under pressure in a direction towards the laminated body 110b. 
Accordingly, the laminated body 110b is sealed at either end of each of communicating through holes by the end member 10c. 
In the honeycomb filter 300 having this kind of structure, exhaust gases flowing into the through hole 11b having an opening at one end face are allowed to flow out from another through hole 11b having an opening at the other end face after passing through the wall portion 13b. While the exhaust gases flow to pass through the wall portion 13b, PM contained in the exhaust gases is captured by the wall portion 13b, and thus, the exhaust gases are purified.
The contents of WO2005/005018 A1 and WO2005/000445 A1 are incorporated herein by reference in their entirety.